[cmquer]

The quantitative analysis of aspirin in aspirin containing tablet by UV-visible molecular absorption spectrometry may not very precise since the tablet may contain impurities.

I suggest the high-performance liquid chromatographic method a better instrumental method for solving the problem because HPLC enables accurate quantitation. Am I right?

[Arkcon]

Close ... what else does HPLC provide you for a sample that allows accurate quantitation?

*HINT*  Once the technicians at work asked what all these machines, HPLC's and gas chromatographs do.  I told him how we used them to analyze final product for accurate amounts of each component.  And he said it was "sad".  I said, "Ummm...sad?  What do you mean?"  He said, "Do you have to ... them?   Can't they stay together, and try to make it work, for the sake of the children."   He was really stretching far for that joke.

Oh, and for the record, when analyzing a tablet containing aspirin, I've made accurate quantitations both by HPLC and spectrophotometry.  It really all does depend on the method.

[enahs]

I would imagine Aspirin to be fluorescence, and that it is very likely you could find an excitation and emission wavelength that would not be influenced by other junk in the system.